<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>document.write 输出流</title>
</head>
<script>
    function myFunction() {
        document.write("我是覆盖的内容");
    }
</script>
<body>

<h1>这是一个标题</h1>

<script>
    document.write("我是增加的内容");
</script>

</body>
<script>
    document.write("我的在body和html之间的数据");
</script>
</html>

<script>
    window.onload = function(){
        myFunction();
    }
</script>

